Driving an electric Mitsubishi i-MiEV to work this week may well have spared the lives of a couple of trees somewhere on this blue-green planet, but if you chopped me down instead, you'd probably find some extra rings that weren't there the day before.
Few experiences have done more to spike my blood pressure or turn my hair grey - sorry, greyer - than taking an electric car home for the first time.
I live 75 kilometres from my office. That sounds like a doddle for a car with an official range of 160 kilometres, although anecdotal real-world evidence suggests 120 kilometres is closer to the mark. Even so, I slide the Mitsubishi's old-fashioned fixed key - not even a folding jobbie, disappointingly - into my pocket without a second thought.
Disconnecting the i-MiEV's special power plug from the 15-amp plug we've had specially fitted in our office garage for just this day, I throw the plug and cable in the boot. I'm pretty sure I'll need to use it at home, to make sure I can do the return trip.
As I slide behind the wheel for the first time and turn the key, there's a loud beep, then silence, with an illuminated ''ready'' lamp the only clue I'm good to go.
Before slotting the automatic gear lever into ''drive'', I cycle through the rudimentary trip computer to find a page showing the car's estimated range.
At full charge it appears I've got a total of 133 kilometres at my disposal. It's not the 160 I'd hoped for, but a quick calculation indicates I've still got an almost 60-kilometre buffer up my sleeve to make it home. Easy-peasy.
The first couple of kilometres of my trip pass uneventfully, as I savour the sounds of silence from beneath the bonnet and settle into the car's unique rhythm. With a single-speed gearbox, it's a bit like driving a golf cart, although as soon as you step off the accelerator the i-MiEV immediately washes off speed rather than coasting, as most cars do.
Nosing onto the freeway and gently accelerating up to 100km/h, I glance at the range indicator. Uh-oh. It's not so much dropping as plummeting, shedding a kilometre from the range indicator for every 600 metres I travel.
It's at this point - with 70 kilometres still to travel and the range indicator ticking down at this alarming, inexorable pace - that I realise I may have bitten off more than the diminutive i-MiEV can chew.
Pulse suddenly racing, I snap the radio off and double-check that the airconditioning is shut down. I curse a couple of energy-sapping quick takeoffs I'd done a few minutes previously, committed in a parallel universe of ignorant bliss.
In the space of moments I transform into a hypermiler - those people who go to utterly ridiculous lengths to squeeze the absolute maximum range from a car's fuel tank, stripping down to their underwear to reduce weight and never using more than about 10 per cent of the engine's power.
It's a consuming occupation, feathering the accelerator pedal and intently watching a power-use gauge mounted in the dashboard in a desperate bid to keep the needle to the left of centre where it teeters over a smug green ''eco'' indicator - well away from the energy-sapping ''power'' indication on the far right.
However, take your foot off the accelerator or press the brake and the needle veers left into a blue ''charge'' section. And, joy of joys, the battery-range indicator pauses for a moment and then actually adds a kilometre. Yes, adds! This is uncharted territory; I've never before driven a car where the fuel needle goes any way but down.
It's in that brief moment that a light bulb switches on somewhere in the dark recesses of my skull. For the first time it's clear to me - in a practical sense, rather than a theoretical one - that electric cars actually make sense. Although not strictly in the way I'm intending to use this one.
By now we've cleared the city fringe congestion and its now-welcome braking opportunities, and there's nothing but unfettered freeway for another 50 kilometres. The range indicator has dived into double figures and battery life is once again melting away like an ice-cream left in the sun.
With no cruise control fitted to the i-MiEV, I'm super-vigilant for the rest of the trip, modulating my throttle with care and maintaining the most constant speed I can on the long, straight, flat, boring road home that I typically curse but today is my best friend.
Painfully aware of a stout headwind that's buffeting the tiny car, costing more of my precious electricity, I even try drafting a few trucks, allowing them to punch a hole in the air for me to follow.
To do it properly, though, I need to get in too close behind them for comfort or safety. I'd still rather run out of juice than end up smeared across the back of one of these behemoths.
After what seems like a tension-packed eternity my home town finally comes into view and - oh, joy - there's still 31 kilometres on the indicator. I pray it's accurate and that the 10 kilometres of stop-start traffic I still have to negotiate will play to the i-MiEV's regenerative strengths. It does.
I finally pull into my driveway with an indicated 27 kilometres of range left, relieved and exhilarated in equal measures.
Using a 15-amp adaptor lead supplied by my friendly sparky, I pull out the i-MiEV's hefty charge lead and plug in, sanguine in the knowledge that 133 kilometres of range will comfortably get me to work the next day.
Except that's not exactly how it turns out.
In the morning the lights on the charge lead show the i-MiEV has taken its full measure of lightning juice, yet the range indicator shows I now have just 110 kilometres to get to the next plug, in the work garage. For reasons unclear, the little Mitsu has taken a short fill. Today, of all days.
My schoolboy maths is copping another workout. I started with 133 kilometres the day before and ended with 27 kilometres, making 106 kilometres the magic number and four kilometres my theoretical buffer. But this morning I also have two children to drop off at school before I can hit the highway. Hello high blood pressure, my old friend.
As I negotiate school traffic in a hilly part of town, the range falls to 104 kilometres, so I drop the transmission from ''drive'' into ''braking'' mode, which ratchets up energy regeneration in stop-start traffic and hilly going in return for dulled responsiveness.
The change is immediate - my range quickly rebounds to 110 kilometres, then winds all the way up to 117 kilometres in 80km/h stop-start conditions before the i-MiEV hits the highway proper.
That light in the back of my brain is on again and this time it's a shining beacon. I finally understand what this car is capable of and I like it.
The rest of the drive is tense but bearable because it's quickly apparent that a tailwind means I'm getting about 700 metres to 800 metres each indicated kilometre of range, rather than yesterday's 600 metres.
I drive into the work garage with 44 kilometres still showing on the range indicator. It's a good result for my 75-kilometre journey, given I started with 110 kilometres on the clock. It's worth noting, though, that both trips were completed without aircon, radio, headlights or any other battery-draining mod cons. A hot day, or a cold night, would be a far sterner test.
Range anxiety, as both I and my doctor can now attest, is a very real beast. The flip side, though, is a tangible feel-good factor and engrossing involvement that could easily become addictive.
I passed about 10 petrol stations during my i-MiEV experience and the first few - in my anxiety-addled mind - gave me pause to consider that they could no longer help me. I was on my own out there until I could reach the next electric plug.
Several more, though, were an opportunity to mentally thumb my nose at the fossil-fuel reliance with which we've all grown up.
The i-MiEV, while fascinating and illuminating, is far from the perfect car. It's extremely expensive ($48,800 plus on-road costs) for a tiny four-seat hatchback with rudimentary dynamics and the comfort and equipment levels of cars half its price.
But it's the first of many fuel-free cars that will hit the market here and consequently deserves kudos as a trailblazer.
Clearly the i-MiEV and other similarly conceived electric cars aren't designed to travel inter-city distances, but the fact that this one did - with the caveat of severe restrictions on driving style and comfort - points to a bright future as the technology develops and range limitations (and anxieties) are gradually lifted.